Remote Fuse Operation Indicator Assemblies and Related Systems and Methods

ABSTRACT

A fuse operation indicator assembly includes an elongate tube having first and second ends, a fuse striker receiving member at the first end of the tube and configured to receive a fuse striker, an actuating member at the second end of the tube and configured to be actuated responsive to the fuse striker member, and a detector configured to detect actuation of the actuating member.

CLAIM OF PRIORITY

The present application is a divisional of U.S. application Ser. No.14/245,457, filed Apr. 4, 2014, the disclosure of which is herebyincorporated by reference herein in its entirety.

BACKGROUND

Fuses are used for overcurrent protection in a wide variety ofelectrical equipment, such as switchgear. Some fuses have an indicatorpin or striker pin that extends out of the fuse cap when the fuse isblown. However, such designs generally require an operator or technicianto closely inspect the fuse to determine its state of operation. Forexample, the technician must step in front of the switchgear and openthe switchgear door to see the indicator pin.

A technician should remain away from the switchgear to keep thetechnician away from potential arc flash energy. Therefore, it isdesirable to remotely monitor fuse operation.

SUMMARY

Some embodiments of the present invention are directed to a fuseoperation indicator assembly. The assembly includes an elongate tubehaving first and second ends. The assembly includes a fuse strikerreceiving member at the first end of the tube and configured to receivea fuse striker. The assembly includes an actuating member at the secondend of the tube and configured to be actuated responsive to the fusestriker member. The assembly includes a detector configured to detectactuation of the actuating member.

In some embodiments, the tube is electrically insulating. The tube mayhave a length of between about 2 and 4 feet.

The striker receiving member may be configured to displace a fluid inthe tube when the striker receiving member receives the fuse strikersuch that the actuating member is displaced. The striker receivingmember may include a spring-loaded piston that is configured to displacethe fluid.

In some embodiments, the striker receiving member includes aspring-loaded piston that is configured to generate a puff of airthrough the tube when the striker receiving member receives the fusestriker such that the actuating member is displaced by the puff of air.

The detector may be an electric switch that is configured to generate anelectrical signal when the actuating member is actuated. The electricswitch may be electrically connected with an indicator that isconfigured to receive the electrical signal and indicate that a fuseassociated with the fuse striker is blown in response to the electricalsignal.

Some other embodiments of the present invention are directed to aswitchgear. The switchgear includes a housing and a plurality of fusesmounted within the housing. Each fuse has a striker pin that is ejectedfrom the fuse when the fuse is operated. The switchgear includes aplurality of fuse operation indicator assemblies mounted within thehousing, one fuse operation indicator assembly for each fuse. The fuseoperation indicator assembly includes electrically insulating elongatetube having first and second ends. The fuse operation indicator assemblyincludes a fuse striker receiving member at the first end of the tube,the fuse striker receiving member positioned and configured to receivethe fuse striker pin when it is ejected from the fuse. The fuseoperation indicator assembly includes an actuating member at the secondend of the tube and configured to be actuated responsive to the fusestriker member. The fuse operation indicator assembly includes adetector configured to detect actuation of the actuating member. Thedetector and the fuse are mounted in the housing in a spaced-apartrelationship.

In some embodiments, the striker receiving member is configured todisplace a fluid in the tube when the striker receiving member receivesthe fuse striker pin such that the actuating member is displaced by thedisplaced fluid.

The detector may be an electric switch that is configured to generate anelectrical signal when the actuating member is actuated. The fuseoperation indicator assembly may include a mounting block mounted in thehousing. The electric switch may be mounted on the mounting block. Theactuating member may be held adjacent the electric switch by a clampingdevice that is mounted to the mounting block.

In some embodiments, the switchgear includes a plurality of indicatorsoutside the housing. Each indicator may be electrically connected with arespective electric switch. Each indicator may be configured to receivethe electrical signal and, in response, indicate that the fuse isoperated.

The switchgear may include a controller and a display. The display maybe outside the housing. The controller may be electrically connectedwith each switch of the plurality of fuse operation indicatorassemblies. The controller may be configured to receive electricalsignals from the switches and control the display to displayindentifying information associated with the electrical signals. Theidentifying information may include an identification and/or location ofone or more fuses that have operated

In some embodiments, the switchgear includes a controller and atransceiver. The controller may be electrically connected with eachswitch of the plurality of fuse operation indicator assemblies. Thecontroller may be configured to receive electrical signals from theswitches and control the transceiver to wirelessly transmit identifyinginformation associated with the electrical signals to an outside device.The identifying information may include an identification and/orlocation of one or more fuses that have operated

Some other embodiments are directed a method for remote monitoring ofthe operation of a fuse. The method includes providing a fuse operationindicator assembly including an elongate tube having a fuse strikerreceiving member at a first end of the tube and an actuating member at asecond, opposite end of the tube. The method includes receiving a fusestriker pin of a fuse at the fuse striker receiving member. The methodincludes actuating the actuating member responsive to receiving the fusestriker pin at the fuse striker receiving member. The method includesdetecting the actuation of the actuating member. The method includesindicating that the fuse has operated responsive to detecting theactuation of the actuating member

In some embodiments, the indicating step includes providing a remoteindication that the fuse has operated.

It is noted that any one or more aspects or features described withrespect to one embodiment may be incorporated in a different embodimentalthough not specifically described relative thereto. That is, allembodiments and/or features of any embodiment can be combined in any wayand/or combination. Applicant reserves the right to change anyoriginally filed claim or file any new claim accordingly, including theright to be able to amend any originally filed claim to depend fromand/or incorporate any feature of any other claim although notoriginally claimed in that manner. These and other objects and/oraspects of the present invention are explained in detail in thespecification set forth below.

Further features, advantages and details of the present invention willbe appreciated by those of ordinary skill in the art from a reading ofthe figures and the detailed description of the preferred embodimentsthat follow, such description being merely illustrative of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of system including a fuse, a fuseoperation indicator assembly and a switch according to some embodiments.

FIG. 2A is a fragmentary perspective view of the fuse and the fuseoperation indicator assembly of FIG. 1 with a fuse striker pin in aretracted state.

FIG. 2B is a fragmentary side view of the fuse and the fuse operationindicator assembly of FIG. 2A.

FIG. 3A is a fragmentary perspective view of the fuse and the fuseoperation indicator assembly of FIG. 1 with a fuse striker pin in anejected state.

FIG. 3B is a fragmentary side view of the fuse and the fuse operationindicator assembly of FIG. 3A.

FIG. 4A is an exploded, fragmentary perspective view of the fuseoperation indicator assembly and the switch of FIG. 1.

FIG. 4B is an assembled, fragmentary perspective view of the fuseoperation indicator assembly and the switch of FIG. 4A.

FIG. 5 is a perspective view of a piece of electrical equipment withfuses mounted therein.

FIG. 6 is a block diagram illustrating a piece of electrical equipmentwith the system of FIG. 1 installed therein.

FIG. 7A is a schematic illustration of system including a fuse, analternative fuse operation indicator assembly and a switch according tosome embodiments, with a fuse striker pin in a retracted state.

FIG. 7B is a schematic illustration of the system of FIG. 7A with thefuse striker pin in an ejected state.

FIG. 8A is a schematic illustration of system including a fuse, afurther alternative fuse operation indicator assembly and a switchaccording to some embodiments, with a fuse striker pin in a retractedstate.

FIG. 8B is a schematic illustration of the system of FIG. 8A with thefuse striker pin in an ejected state.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which illustrativeembodiments of the invention are shown. In the drawings, the relativesizes of regions or features may be exaggerated for clarity. Thisinvention may, however, be embodied in many different forms and shouldnot be construed as limited to the embodiments set forth herein; rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the invention to thoseskilled in the art.

It will be understood that when an element is referred to as being“coupled” or “connected” to another element, it can be directly coupledor connected to the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlycoupled” or “directly connected” to another element, there are nointervening elements present. Like numbers refer to like elementsthroughout. As used herein the term “and/or” includes any and allcombinations of one or more of the associated listed items.

In addition, spatially relative terms, such as “under”, “below”,“lower”, “over”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is inverted, elements described as “under” or “beneath”other elements or features would then be oriented “over” the otherelements or features. Thus, the exemplary term “under” can encompassboth an orientation of over and under. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

Well-known functions or constructions may not be described in detail forbrevity and/or clarity.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

A system 10 for remote monitoring of fuse operation according to someembodiments is illustrated in FIG. 1. The system 10 includes a fuse 20,a fuse operation indicator assembly 40 and a switch 70. The fuseoperation indicator assembly 40 extends between the fuse 20 and theswitch 70.

The fuse 20 may be a medium-voltage fuse (e.g., the fuse 20 may beconfigured to protect 2.4-145 kV systems). Referring to FIG. 1, the fuse20 includes a tubular housing 22 formed of a suitable electricallyinsulating material. End caps 24, 26 are disposed at opposite ends ofthe housing 22 and are formed of a suitable electrically conductingmaterial.

Disposed within the housing 22 of the fuse 20 is at least one fusibleelement 28, as illustrated in FIG. 3A. Current through the fuse 20 isconducted under normal conditions by the fusible element 28. A strikeror striker pin 30 is in the fuse 20, with one end of the striker pin 30adjacent to or abutting the end cap 24. The striker pin 30 is shown in aretracted position in FIG. 3A.

An excessive current causes the fusible element 28 to melt and the fuse20 is operated (i.e., the fuse is blown). In response, the striker pin30 is ejected from the fuse 20 away from the end cap 24. The striker pin30 is shown in an ejected or extended position in FIG. 3B. The strikerpin 30 may be ejected in any manner known to those of skill in the art.For example, the striker pin 30 may be spring-actuated or pyrotechnic orpowder-actuated as described in U.S. Pat. Nos. 4,322,706 and 5,367,281,the disclosures of which are incorporated herein in their entireties.

Referring to FIGS. 1, 3A and 3B, the fuse operation indicator assembly40 includes an elongated tube 42. The tube 42 is formed of anelectrically insulating material, such as a polymer. At a first end 44of the tube 42 is a striker receiving member 46. At a second, oppositeend 48 of the tube 42 is a switch actuating member 50. In someembodiments, the tube 42 has a length of at least 2 feet. In someembodiments, the tube 42 has a length of between about 2 to 4 feet.

As illustrated, the striker receiving member 46 is mounted to a bracket48 which in turn is mounted to a bracket 50 of the fuse 20. The brackets48, 50 may include slots 48 s, 50 s to facilitate adjustment of theposition of the striker receiving member 46 relative to the fuse 20(FIG. 2A).

The striker receiving member 46 may include a spring-loaded piston.Specifically, referring to FIG. 3A, the illustrated striker receivingmember 46 includes a trip indicator piston 52 and a piston spring 54.The piston spring 54 biases the piston 52 toward the fuse 20. Thestriker receiving member 46 also includes a trip indicator body 56. Thefirst end 44 of the tube 42 is received in the body 56.

As illustrated in FIGS. 4A and 4B, the switch 70 is mounted to amounting block 74. The mounting block 74 may be mounted to a mountingsurface 75, such as a mounting surface in electrical equipment (e.g.,switchgear). The switch 70 may be an electric switch such as a miniaturesnap-action switch or a micro switch, for example. As illustrated, theswitch 70 includes an actuator 76 and a plurality of contacts 78. Asunderstood by those skilled in the art, upon actuation of the actuator76, the contacts 78 may be closed or opened and an electrical signal maybe detected or provided from the switch 70.

The switch actuating member 50 extends from the end of the tube 42, andthe tube 42 is mounted to the mounting block 74 by a clamp 80. As shownin FIG. 4A, a pad 82 can be positioned between the tube 42 and themounting block 74. The pad 82 may be formed of silicone, for example.The pad 82 may provide slip-resistance for the tube 42 (e.g., when airpressure is provided through the tube, as described below) and/or may bedeformable to reduce deformation of the tube 42 as the clamp 80 istightened to the mounting block 74.

The switch actuating member 50 is positioned a distance d1 from theswitch actuator 76. In some embodiments, the distance d1 is betweenabout 0.1 and 0.5 inches. In some embodiments, the distance d1 is about0.25 inches.

In some embodiments, the switch 70, the mounting block 74 and associatedcomponents are included as part of the fuse operation indicator assembly40.

The system 10 is configured to remotely monitor fuse operation,including providing remote indication that the fuse 20 has blown. Asdiscussed above, when the fuse 20 is blown, the striker pin 30 movesfrom the retracted position (FIG. 3A) to the extended position (FIG.3B). The striker pin 30 contacts and forcibly or rapidly depresses thepiston 52 to the position shown in FIG. 3B. A puff or pulse of air isgenerated, and the puff or pulse of air travels through the tube 42 fromthe first end 44 to the second end 48 of the tube 42.

The puff or pulse of air urges the switch actuating member 50 in thedirection indicated by the arrow A1 in FIG. 4B. The switch actuatingmember 50 contacts and actuates the switch actuator 76 and closes anelectrical circuit associated with one of the switch contacts 78.

It is contemplated that the puff or pulse of air may provide sufficientforce to actuate the switch actuator 76. For example, the switchactuating member 50 may be omitted and the puff or pulse of air emittedfrom the second end 48 of the tube 42 may actuate the switch actuator76. Alternatively, the switch actuating member 50 may include an orificeor the like through which the puff or pulse of air is emitted to actuatethe switch actuator 76.

Turning now to FIG. 5, one or more of the fuses 20 may be mounted in apiece of electrical equipment, such as switchgear 100. The switchgear100 includes a housing 100 h and a front panel 110. The front panel 110is shown in an open position exposing a cavity 100 c defined by thehousing 100 h and the front panel 110. The housing 100 h has an interiorsurface 100 i and an exterior surface 100 e. The mounting surface 75 forthe switch 70 and/or the mounting block 74 may be on the interiorsurface 100 i or elsewhere in the housing 100 h.

Therefore, in some embodiments, the system 10 may be located in thehousing 100 h. As shown in FIG. 6, a plurality of fuses 20 ₁, 20 ₂, 20_(N) are positioned in the housing 100 h of the switchgear 100. Also asshown, a plurality of indicator assemblies 40 ₁, 40 ₂, 40 _(N) and aplurality of switches 70 ₁, 70 ₂, 70 _(N) are provided in the housing100 h. Each indicator assembly 40 is positioned between respective onesof the fuses 20 and switches 70 in the manner described above. One ofthe switch contacts 78 for each switch 70 may be electrically connectedwith an indicator 104 (e.g., an LED) that may be positioned on theexterior of the housing 100 h of the switchgear 100, on a front door orpanel 110 of the switchgear 100, or otherwise positioned away from theswitchgear 100. Although only switch 70 ₁ is shown electricallyconnected to an indicator 104, it is contemplated that switch 70 ₂and/or 70 _(N) are connected to indictors 104 such that a technician orthe like can identify which of the fuses 20 is operated or blown (e.g.,the indicators 104 may be color coded or may be positioned to provideinformation identifying the fuse 20 and/or the location thereof).

In some embodiments, the switches 70 may be electrically connected to acontroller 102. The controller 102 may be configured to operate theindicators 104. In some embodiments, the controller 102 is configured tooperate a display 106 which may be provided on the exterior of theswitchgear housing 100 h, on the front panel 110, or otherwisepositioned away from the switchgear 100. The display 106 may beconfigured to display operating conditions of the fuses 20, includingidentifying operated or blown fuses. The display 106 may provideidentifying information such as the location(s) of the blown fuse(s).

In some embodiments, the controller 102 is configured to operate atransceiver 108 that is configured to transmit wireless signals to anelectronic device 200 such as a computer (desktop, laptop, tablet,etc.), a smartphone or some other wireless communication terminal. Thetransceiver 108 may wirelessly transmit data including identifyinginformation such as operating conditions of the fuses, the location ofany blown fuses, etc. The electronic device 200 may include atransceiver 202 to receive the wireless signals from the switchgeartransceiver 108 and may include a display 204 to view identifyinginformation sent by the switchgear transceiver 108. The electronicdevice 200 may also send wireless signals to the switchgear 100, forexample to query the controller 102 as to the operating condition of thefuses 20 (e.g., using user interface 206). A wireless interface betweenthe switchgear 100 and the electronic device 200 may be any suitabletype of wireless interface. According to some embodiments, the wirelessinterface is a radiofrequency (RF) wireless interface. The wirelessinterface may be a wireless local area network (WLAN) interface, adirect point-to-point wireless interface and/or a cellular communicationwireless interface.

An alternative fuse operation indicator assembly 40′ is illustrated inFIGS. 7A and 7B. The assembly 40′ includes an electrically insulatingmember 90 that may be rigid or semi-rigid (e.g., a rod or cable). Asillustrated, the member 90 is slidably held in the tube 42, although thetube 42 may be omitted or another sheath-like structure can be providedin its place. The member 90 has a first end 91 at or near the tube firstend 44 and the striker receiving member 46; the member 90 has anopposite second end 92 at or near the tube second end 48. In the stateshown in FIG. 7A, the second end 92 is positioned adjacent the switch 70and the switch actuator 76.

As described above, when the fuse 20 is blown, the striker pin 30 isejected from the fuse 20 and forcibly contacts the striker receivingmember 46. As shown in FIG. 7B, the rod 90 translates such that the rodsecond end 92 contacts the switch actuator 76. In some embodiments, andas shown, the rod 92 slides out of the tube second end 48 and contactsthe switch actuator 76. The switch 70 sends a signal to provide remoteindication that the fuse has operated or blown in the manner describedabove.

Another alternative fuse operation indicator assembly 40″ is illustratedin FIGS. 8A and 8B. The assembly 40″ includes a light-transmittingflexible cable 94. The cable may be a fiber optic cable, for example.The cable 94 has a first end 95 at or near the striker receiving member46 and a second, opposite end 96 at or near a switch 70′. The switch 70′is substantially similar to the switch 70 described above except theswitch 70′ includes a light detector 99. In the illustrated embodiment,a light emitter 98 is provided at or near the striker receiving member46. For example, the light emitter 98 may be in the body 56. Light istransmitted through the cable 94 from the first end 95 to the second end96 and received at the light detector 99, as illustrated by the arrowsA2.

As described above, when the fuse 20 is blown, the striker pin 30 isejected from the fuse 20 and forcibly contacts the striker receivingmember 46. As shown in FIG. 8B, the flexible cable 94 bends, asindicated by the bend 94 b. Light emitted by the light emitter 98,indicated at arrow A3, is not received at the light detector 99 becauseof the bending of the cable 94. As a result, the switch 70′ sends asignal to provide remote indication that the fuse has operated or blownin the manner described above.

It will be understood that the alternative fuse operation indicatorassemblies 40′ or 40″ may be used in place of the fuse operationindicator assembly 40. For example, one of the fuse operation indicatorassemblies 40′ or 40″ may be used in the system 10 (FIG. 1) or in theswitchgear 100 (FIG. 6).

Embodiments of the invention allow a user to remotely be aware of fuseoperation or lack of operation. It is undesirable to use metal wires orthe like to provide signals because the conductive metal wires may causeelectrical failures in the equipment. Embodiments of the presentinvention use elongated electrically insulating (non-conductive) memberssuch as plastic tubes and rods as well as non-conductive air or lightthat will not cause flashovers. Embodiments of the invention allow forfuse operation or lack or operation to be viewed remotely. Accordingly,a technician or user can safely observe fuse operation well away fromthe switchgear and away from potential arc flash energy.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention. Therefore,it is to be understood that the foregoing is illustrative of the presentinvention and is not to be construed as limited to the specificembodiments disclosed, and that modifications to the disclosedembodiments, as well as other embodiments, are intended to be includedwithin the scope of the invention.

That which is claimed is:
 1. A fuse operation indicator assembly,comprising: an elongate tube having first and second ends; a fusestriker receiving member at the first end of the tube and configured toreceive a fuse striker; an actuating member at the second end of thetube and configured to be actuated responsive to the fuse strikermember; and a detector configured to detect actuation of the actuatingmember.
 2. The assembly of claim 1, wherein the tube is electricallyinsulating.
 3. The assembly of claim 1, wherein the tube has a length ofbetween about 2 and 4 feet.
 4. The assembly of claim 1, wherein thestriker receiving member is configured to displace a fluid in the tubewhen the striker receiving member receives the fuse striker such thatthe actuating member is displaced.
 5. The assembly of claim 4, whereinthe striker receiving member comprises a spring-loaded piston that isconfigured to displace the fluid.
 6. The assembly of claim 1, whereinthe striker receiving member comprises a spring-loaded piston that isconfigured to generate a puff of air through the tube when the strikerreceiving member receives the fuse striker such that the actuatingmember is displaced by the puff of air.
 7. The assembly of claim 1,wherein the detector is an electric switch that is configured togenerate an electrical signal when the actuating member is actuated. 8.The assembly of claim 7, wherein the electric switch is electricallyconnected with an indicator that is configured to receive the electricalsignal and indicate that a fuse associated with the fuse striker isblown in response to the electrical signal.